Conventional LED lighting devices commonly make use of a plurality of LEDs of a single polarity in series. These conventional devices are commonly mounted on bus bars, etched circuit boards or some similar wiring to which each of the LEDs is connected. A disadvantage of these conventional devices is that the LEDs may become inoperative over a period of time from burnout due to continued usage. As well, customers must assure that polarity is correct upon connection.
Recently improved lighting devices have been designed using LEDs connected in parallel and having opposite polarities. Specifically, pairs of LEDs with opposite polarities are connected in parallel, and the pairs of LEDS are further connected in series. The LEDs connected in parallel with opposite polarities do not suffer damage during reverse voltage. This is because the first LED in each pair, operating in forward voltage, clamps the voltage to a voltage lower than the break down voltage of second LED in each pair, which has the opposite polarity.
The improved devices have an advantage over the conventional devices in that alternating currents can be used to light half of the LEDs when current flows in one direction, and light the other half of the LEDs when current flows in the other direction. The fact that LEDs can alternately illuminate extends the useful life of the lighting device. That is to say, because LEDs can alternately illuminate, LED burnout takes longer to occur.
Although alternating current LED devices are an improvement over the conventional series-connected LED devices, their application has been limited to circuit board style lighting devices. Lacking in the art is an opposite polarity, laminated, low-cost production LED lighting device that is constructed for rugged environments such as outdoor lighting. The embodiments of the present disclosure present such a device.